Move over, Hope Diamond. The most famous gems on Earth have new competition in the form of a planet made largely of diamond, astronomers say.

The alien planet, a so-called “super-Earth,” is called 55 Cancri e and was discovered in 2004 around a nearby star in our Milky Way galaxy. After estimating the planet’s mass and radius, and studying its host star’s composition, scientists now say the rocky world is composed mainly of carbon (in the form of diamond and graphite), as well as iron, silicon carbide, and potentially silicates.

‘Pure Diamond’

At least a third of the planet’s mass is likely pure diamond. 55 Cancri e is what’s known as a super-Earth, with a radius twice as wide as that of our own planet, and a mass eight times greater. It speeds around its host star, making a full orbit in just 18 hours (Earth takes 365 days). It is so close in to the star that its surface temperature reaches a scorching 3,900 degrees Fahrenheit (2,100 degrees Celsius), making it probably way too hot for life.

The revelation of the planet’s diamond nature means that it could have very different thermal evolution and plate tectonics processes than Earth, which could create bizarre types of volcanism, seismic activity, and mountain formation.

‘Visible to the Naked Eye’

55 Cancri e is one of five planets encircling a sun-like star called 55 Cancri, which lies about 40 light-years from Earth in the constellation of Cancer. This star is so close it is visible to the naked eye in the night sky. A paper reporting the new findings has been accepted for publication in the journal Astrophysical Journal Letters.

Could a “diamond planet” really exist? Do you think there are other planets out there made of other types of precious gems? Feel free to share your thoughts and ideas regarding this new bright discovery!

Light from an alien “super-Earth” twice the size of our own Earth has been detected by a NASA space telescope for the first time in what astronomers are calling a historic achievement.

NASA’s infrared Spitzer Space Telescope spotted light from the alien planet 55 Cancri e, which orbits a star 41 light-years from Earth. A year on the extrasolar planet lasts just 18 hours. The planet 55 Cancri e was first discovered in 2004 and is not a habitable world. Instead, it is known as a super-Earth because of its size: The world is about twice the width of Earth and has about eight times the mass of Earth. But until now, scientists have never managed to detect the infrared light from the super-Earth world.

Past observations of the planet 0by the Spitzer Space Telescope have suggested that one-fifth of 55 Cancri e is made up of lighter elements, including water. But the extreme temperatures and pressures on 55 Cancri e would create what scientists call a “supercritical fluid” state. Supercritical fluids can be imagined as a gas in a liquid state, which can occur under extreme pressures and temperatures. On Earth, water can become a supercritical fluid inside some steam engines.

Spitzer’s new look at 55 Cancri e is consistent with supercritical-fluid waterworld theory. The planet is likely a rocky world covered with water in a supercritical fluid state and topped off with a steam blanket, researchers said. The research is detailed in the Astrophysical Journal.

“When we conceived of Spitzer more than 40 years ago, exoplanets hadn’t even been discovered,” said Michael Werner, Spitzer project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Because Spitzer was built very well, it’s been able to adapt to this new field and make historic advances such as this.”